The Orientation of Sand Grains under Conditions of "Unidirectional" Fluid Flow: 1. Theory and Experiment

Late Quaternary palaeosols in the Yangtze Delta, China, and their palaeoenvironmental implications

“…For comprehensive reviews of the theory and application of the AMS technique in geology, see Hrouda (1982), MacDonald and Ellwood (1987), Borradaile (1988), Jackson and Tauxe (1991), Rochette et al (1992), and Tarling and Hrouda (1993). Hydrodynamic forces were found to be the dominant factor controlling the orientation of sediment grains in most flow regimes and the grains offer the least resistance with their long axes oriented in the flow direction (Rusnak, 1957). This was subsequently confirmed to be the dominant mode of grain alignment (e.g., Rees, 1965;Ellwood and Ledbetter, 1977).…”

“…The preferred orientation of magnetic minerals revealed by AMS measurement has been used to infer hydrodynamic processes during their deposition (Rees, 1965;Taira and Lienert 1979;Pickering et al, 1992). AMS investigation has proved useful in identifications of palaeoflow direction (e.g., Rusnak, 1957;Ellwood and Ledbetter, 1977;Pickering et al, 1992Pickering et al, , 2001, and in differentiating late Quaternary coastal sedimentary environments (e.g., Chen et al, 1998;Liu et al, 2001Liu et al, , 2005. The AMS technique has been applied comprehensively in studies of sediments from various environments, such as loess (Liu et al, 1990;Lagroix and Banerjee, 2002;Zhu et al, 2004), tidal flat sediments (Cong et al, 1997;Chen et al, 1998), lake sediments (Rosenbaum et al, 2000;Schneider et al, 2004), and fluvial deposits (Sangode et al, 2001;Zhang et al, 2004).…”

Identifying ash flow sources with directional data: An application to the Kizilkaya ignimbrite, central Anatolia

“…In spite of vertical grain-size variations, the areal MP5 variation is considered here to be more significant than thickness: it leads to the proposal of a dispersal axis trending roughly ii'om west to east. [Rusnak, 1957]. This method is well suited for the study of widespread ignimbrites as it allows rapid measurements at many sites and so has been peribrined on the Kizilkaya unit.…”

Vent area and depositional mechanisms of the Upper Member of the Neapolitan Yellow Tuff (Campi Flegrei, Italy): new insights from directional fabric through image analysis

“…The Tukey χ 2 test (Rusnak 1957) provides information on the occurrence of a significant deviation from a theoretical circular distribution. χ 2 values exceeding 5.99 (at 5% of significance level) proves the existence of anisotropy which, under the hypothesis of unimodality, also proves the occurrence of a preferred orientation of particles.…”